(Q7).Find the 10th and nth term of G.P.: 5, 25, 125,…..

Given G.P.: 5, 25, 125,....

a = , r =
a2
a1
 =
=

an = a.rn-1 = × ()n-1 = 1+n-1 = n

a10 = a.r9 = × 9 = 10

∴ a10 = 10; an = n